A mixed variety of the disease is of frequent occurrence, the 

 mucosa showing the characteristic deposits and the skin pox 

 lesions. It is quite evident in these cases that the disease 

 spreads from one location to the other, and the difference in 

 the lesions is due to the difference in the structure of the tissue 

 involved. 



General Symptoms. In the early stages before much sec- 

 ondary infection takes place, there are no marked general 

 symptoms. Later marked general symptoms appear. The 

 birds show dullness, assume a sitting posture, wings are held 

 pendant, plumage becomes rough and the patients show much 

 depression. The comb and wattles grow bluish red in color, 

 later pale and cold. In the colder climates the disease often 

 assumes a subacute or chronic form. While in warmer cli- 

 mates the acute form is more often observed. Frequently, how- 

 ever, the disease assumes the character of a chronic catarrh. 



Diagnosis 



The disease usually makes its first appearance in the fall 

 of the year and often occurs as the cutaneous form; it may be 

 overlooked, especially if the birds are on the range. The 

 mucous membrane form usually makes its appearance soon 

 after housing for the winter. The sneezing, mouth breathing, 

 occluded nostrils, and an occasional inflamed eye, are significant 

 especially when rapidly spreading through the flock. Soon 

 after, a few will refuse food and appear depressed. 



It must also be suspected when similar symptoms appear 

 after adding new birds to a healthy flock or returned birds 

 from shows. 



A peculiar characteristic and offensive odor is associated 

 with this disease and poultrymen familiar with it often recog- 

 nize the disease from the odor alone. The same odor is given 

 off by cultures. 



Differential Diagnosis 



Wounds on the skin around the head, usually pick inflicted, 

 appear suspicious, but these heal rapialy without extensive 

 thickening. An injury to the eye, even though serious, will not 

 cause the formation of the characteristic yellow deposit. Dif- 

 ficult respiration, rarely seen in more than one bird in a flock, 



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